Part of Churchill's speech on 20 August 1940 - More Here
'The gratitude of every home in our Island, in our Empire, and indeed
throughout the world, except in the abodes of the guilty, goes out to
the British airmen who, undaunted by odds, unwearied in their constant
challenge and mortal danger, are turning the tide of the World War by
their prowess and by their devotion. Never in the field of human conflict was so much owed by so many to so few.
All hearts go out to the fighter pilots, whose brilliant actions we see
with our own eyes day after day, but we must never forget that all the
time, night after night, month after month, our bomber squadrons travel
far into Germany, find their targets in the darkness by the highest
navigational skill, aim their attacks, often under the heaviest fire,
often with serious loss, with deliberate, careful discrimination, and
inflict shattering blows upon the whole of the technical and war-making
structure of the Nazi power. On no part of the Royal Air Force does the
weight of the war fall more heavily than on the daylight bombers who
will play an invaluable part in the case of invasion and whose
unflinching zeal it has been necessary in the meanwhile on numerous
occasions to restrain…'

— Winston Churchill

Flypast to mark 'hardest day' of Battle of Britain BBC News

... What General
Weygand has called The Battle of France is over. The battle of Britain is about
to begin. Upon this battle depends the survival of Christian civilisation. Upon
it depends our own British life and the long continuity of our institutions and
our Empire. The whole fury and might of the enemy must very soon be turned on
us. Hitler knows that he will have to break us in this island or lose the war.
If we can stand up to him, all Europe may be free and the life of the world may
move forward into broad, sunlit uplands. But if we fail, then the whole world,
including the United States, including all that we have known and cared for,
will sink into the abyss of a new Dark Age made more sinister, and perhaps more
protracted, by the lights of a perverted science. Let us therefore brace
ourselves to our duties, and so bear ourselves that, if the British Empire and
its Commonwealth last for a thousand years, men will still say, "This was
their finest hour".